[compsciphd]

so I did a check, it would seem that gvisor with kvm, mostly works for bare metal, not on existing VMs (nested virtualization).

https://gvisor.dev/docs/architecture_guide/platforms/

"Note that while running within a nested VM is feasible with the KVM platform, the systrap platform will often provide better performance in such a setup, due to the overhead of nested virtualization."

I'd argue then for most people (unless have your own baremetal hyperscaler farm), one would end up using gvisor without kvm, but speaking from a place of ignorance here, so feel free to correct me.